Cobalt resinate and method of



Patented Aug. 25, 1942 COBALT masma'ra AND METHOD OF PRODUCING Herschel Elliottrwilmington, DeL, lssignol' to Hercules Powder Company, Wilmington, Del., a corporationof Delaware No Drawing. Application September 4, 1941,

Serial llo. 409,537

11 Claims. (01. 260100) This invention relates to the production of fused cobalt resinates and more particularly to fused cobalt resinates of improved characteristics and to the method of production thereof.

Cobalt salts of wood or gum rosin have found wide usage as driers in paints and varnishes. Such salts have been made either by a precipitation method involving double decomposition of an alkali metal salt of rosin with a suitable'cobalt compound, or by a fusion process involving fusion of the rosin with a reactive cobalt compound. By the precipitation method it has been possible to produce cobalt resinates containing up to the theoretical cobalt content for the neutral salt. By the fusion method, however, it has been impossible to introduce more than about 3% of cobalt due to the fact that blocking of the resinate occurs when about that amount of cobalt has become combined. For this reason the cobalt resinates produced commercially are usually prepared by the precipitation method. While such a method is more costly than the fusion method it has provided the only means of obtaining the desired higher cobalt contents.

It is an object of this invention to provide fused cobalt resinates of higher cobalt content than has been heretofore possible.

It is another object to provide fused cobalt resinates of high cobalt content which possess many improved characteristics.

g It is a further object to provide a method of producing fused cobalt resinates of higher cobalt content than has been heretofore possible.

Other objects of the invention will appear hereinafter.

The above objects may be accomplished in accordance with this invention by fusing a hydrogenated rosin with a suiiicient amount of a cobalt compound capable of reaction with the hydrogenated rosin, at a temperature in the range of about 200 C. to about 350 C. to give a cobalt resinate of the hydrogenated rosin having a cobalt content greater than the equivalent combining proportion of the hydrogenated rosin based on its acidity and as high as about 18% by weight. The theoretical cobalt content of a hydrogenated rosin in place of ordinary rosin and according to the, described procedure, that clear homogeneous resinates may be prepared without the blocking disadvantage encountered in the production of cobalt resinates from ordinary rosins. Thus, by the process of this invention cobalt resinates containing more than the theoretical combining proportion of cobalt based on the acidity of the rosin .and up to about twice the theoretical cobalt content of cobalt diresinate are made available.

In carrying out the fusion process-oftfi in vention a hydrogenated rosin is'reacted with a cobalt compound capable of reaction therewith to provide a salt. Such a compound may, be-a basic cobalt compound or it may be a cobalt salt of a volatile we'ak acid or any other cobalt compound which under the fusion conditions liberates its cobalt. Suitable cobalt compounds are, for example, cobalt acetate, cobalt formate;----- 'rosin, ,of calcium acetate or other fatty acid salt of calcium or a fatty acid salt of zinc, lead, manganese, etc., may be employed, if desired in conjunction with the cobalt compound.

The reaction is carried out by heating the hydrogenated rosin to a temperature in the range of about 200 C. to about 340 C. and adding the cobalt compound alone or in admixture with a catalytic meta1 compound such as a calcium salt either gradually or at one time, preferably while agitating the mixture. When the catalytic metal compound is used, satisfactory fusion takes 1 place at temperatures as low as 200 C. but when the catalytic material is not employed it is usually desirable to employ a fusion temperature of at least about 275 C. At lower temperatures without the, catalytic material there is a slight tendency to blocking in passing through the reaction stage representing formation of a resinate containing about 3 to 10% of combined cobalt. Considerable foaming accompanies the reaction and it is therefore preferable to agitate during the addition and to carry out the addition 7 W over an extended period. The foaming is-more severe at the lower temperatures and reaction As a catalytic V ends from the hydrogenated rosin. tures of about 275 to about 330 C. are therefore becomes diminished due to volatilization of light Temperapreferable' for the reaction.

The time of reaction required to combine the reactive cobalt compound with the hydrogenated I rosin to produce the high metal content fused cobalt resinates is dependent on the temperature employed, the particular cobalt compound used,

\ 'the degree of agitation, the particular amount of metal being introduced, as well as on other factors. Thus, the reaction time may be varied from about minutes to several hours. It will be desirable to conduct the reaction in an inert atmosphere such as may be provided by carbon dioxide, nitrogen, etc., toprevent oxidation and discoloration of the hydrogenated rosin or the resinate at the elevated temperatures employed.

The hydrogenated rosin which may be employed in the process of the invention may be produced, as is well known in the art, by contacting wood or gum rosin or the acids contained therein with hydrogen and a suitable hydrogenation catalyst. Thus, by contacting rosin in a fluid condition with hydrogen in the presence of an activated base metal hydrogenation catalyst under a pressure in the range of about 200 to 15,000 pounds per square inch and at a temperature of about 125 C. to about 225 C. a hydrogenated product useful in this invention will beobtained.

Hydrogenated rosin may also be obtained by contacting rosin dissolved in a suitable solvent with hydrogen and a noble metal hydrogenation catalyst, as for example platinum, palladium, etc., as is well known in the art. The hydrogenated rosin obtained by any of the above methods will have varying degrees'of saturation depending on the actual conditiohs'employed; For use in the present invention a hydrogenated rosin having a saturation value corresponding to at least about 50 per cent saturation of both double 'bonds of the rosin acid contained in the rosin will be preferred, although rosins of lower saturation may also be employed. Hydrogenated rosins having a saturation of about 50 to about 95 per cent of both double bonds will be particularly desirable in the production of the novel resinates of the invention. After hydrogenation the hydrogenated rosin may be subjected to vacuum distillation to remove the light end or to separate 'any particular fraction. If desired, it may be sub-.

jected to a refining treatmentwith a selective color-body solvent or absorbent as furfural, phenol, fullers earth, etc. The hydrogenated rosin used will generally havean acid number The following specific examples are illustrative oi the various embodiments oi the invention:

\ Example I one hundred parts by weight of a hydrogenated wood rosin saturated to the extent oi 63% 01- both double bonds of the rosin acid contained there- ,in and having an acid number of 158 and a drop melting point of 75 C. were melted and heated to a temperature of 240 C. in a nitrogen atmosphere. A mixture of 86 parts by weight of cobalt Example II One hundred and ten parts by weight of hydrogenated gum rosin having a saturation of 60% of both double bonds of the rosin acid contained therein, an acid number oi 155 anda drop melt- -ing point of 79 C. were melted and heated to'a above about 100 and preferably from about 135 to about 185.

The fused cobalt salts of hydrogenated rosin described in accordance with this invention will be considerably more useful in the commercial fields such as for example, as driers in paints or varnishes, in plastics, adhesives, printing inks,

etc., due to the improved characteristics over prior cobalt resinates. Thus, they will contain a higher cobalt content than has been possible heretofore, which is a very desired advantage. They will also be less subject to oxidation and discoloration at both normal and elevated temperatures and will also be less subject to spontaneous ignition than j the cobalt resinates prepared from ordinary rosin. They will be clear homogeneous resins and will be substantially free of precipitated or suspended matter.

temperature of 255 C. in a nitrogen atmosphere. A mixture 01' 71 parts by weight of cobalt acetate and 10 parts by weight of calcium acetate was then added gradually in small portions at a time with constant agitation and while permitting the reaction to subside before each subsequent addition. The reaction temperature was raised gradually during the addition to a maximum of 325 C. The fused cobalt resinate obtained had smelting point of 215 C., a cobalt content of 13.3% and a calicum content of 2%. It was a clear homogeneous resin.

Example III in Example I, 400 parts by weight of the rosin were melted and heated to a temperature of 280 C. in a carbon dioxide atmosphere. A mix ture of 167 parts by weight of cobalt acetate and 36 parts by weight of calcium acetate was then added gradually in small portions at a time with agitation. The reaction temperature was raised gradually to a maximum of 310 C. during the addition. A total addition time of 70 minutes was employed. The cobalt resinate obtained had a drop melting point of 200 C., a cobalt content of 9%, and a calcium content of 2%.

It will be understood that the details and examples hereinbefore set forth are illustrative only and that the invention as broadly described and claimed is in no way ted thereby.

What I claim and desire to protect by Letter Patent is:

1. A cobalt resinate of a hydrogenated rosin having a cobalt content greater than the equiv alent combining proportion of the hydrogenated rosin'but not in excess of about 18% by weight. 2. A cobalt resinate of a hydrogenated rosin saturated to the extent of at least 50% of both double bonds of the rosin acid contained therein and having a cobalt content greater than the equivalent combining proportion of the hydrogenated rosin but not in excess of about 18% by weight.

3'. A cobalt resinate of' a hydrogenated wood rosin having a cobalt content greater than the equivalent combining proportion of the hydro-.

2,294,287 genated rosin but not in excess of about 18%- by weight.

4. A cobalt resinate of a hydrogenated gum rosin having a, cobalt content greater than the equivalent combining proportion. of the hydrogenated rosin but not in excess of about 18% by weight.

5. The method of producing a cobalt resinate of a hydrogenated rosin having a cobalt content greater than the equivalent combining proportion of the hydrogenated rosin but not in excess of about 18% by weight, which comprises fusing a hydrogenated rosin with a cobalt compound capable of reaction with the hydrogenated rosin, in an amount sufficient to give a resinate of the above defined cobalt content at a temperagigge within the range of about 200 C. to about 6. The method of producing a cobalt resinate of a, hydrogenated rosin having a cobalt content greater than the equivalent combining proportion of the hydrogenated rosin but not in excess of about 18% by weight, which comprises fusing a hydrogenated rosin'with a. cobalt compound capable of reaction with the hydrogenated rosin, in an amount sufficient to give a resinate of the above defined cobalt content and in the presence of a catalytic metal compound at a temperature within the range of about 200 C. to about 350 C.

7. The method of producing a cobalt resinate of a, hydrogenated rosin having a cobalt content greater than the equivalent combining porportion of the hydrogenated rosin but not in excess of about 18% by weight, which comprises fusing a hydrogenated rosin with a cobalt compound capable of reaction with the hydrogenated rosin, in an amount sufiicient to give a resinate of the above defined cobalt content and in the presence of a small amount of a calcium salt as catalyst at a. temperature within the range of about 200 C. to about 350 C.

8. The method of producing a cobalt resinate of a hydrogenated rosin having a cobalt content greater than the equivalent combining proportion of the hydrogenated rosin but not in excess of about 18% by weight, which comprises fusing a hydrogenated rosin with a cobalt compound capable of reaction with the hydrogenated rosin, in an amount sufficient to give a resinate of the above defined cobalt content at a'temperature within the range of about 275 C. to about 330 C. d 9. The method of producing a cobalt resinate of a hydrogenated rosin having a cobalt content greater than the equivalent combining proportion of the hydrogenated rosin but not in excess of about 18% by weight, which comprises fusing'a hydrogenated .rosin with cobalt acetate in an amount suflicient to give a resinate of the above defined cobalt content and in the presence of a small amount of calcium acetate'as catalyst at a temperature within the range of about 275 C. to about 330 C.

10. The method of producing a cobalt resinate of a hydrogenated rosin having a cobalt content greater than the equivalent combining proportion of the hydrogenated rosin but notin excess of about 18% by weight, which comprises fusing a, hydrogenated rosin with a mixture of cobalt oxide and cobaltacetate in an amount suflicient to give a resinate of the above defined cobalt content and in the presence of a small amount of calcium acetate as catalyst at a temperature within the range of about 275 C. to about 330 C. a

11. The method of producing a cobalt resinate of a hydrogenated rosin having a cobalt content greater than the equivalent combining proportion of the hydrogenated rosin but not in excess of about 18% by weight, which comprises fusing a hydrogenated rosin with a mixture of cobalt oxide and aceticacid in an amount sufiicient to give a resinate of the above defined cobalt content and in the presence of a small amount of calcium acetate as catalyst at a temperature within the range of about 275 C. to about 330 C.

HERSCHEL A. ELLIOTT. 

